On Fri, 11 Mar 2011 09:08:59 -0800 (PST), wolfgang
wrote:

[...]

Today there are more options than there were when I built my tooling.
I found the dremel tool speed too high for effective drilling of
steel.

Agreed. Even 1/8" is pushing it with 5000 rpm.

The spacer pin (or bar) is a length of rod that I place between the
bottom edge of the horizontal chuck jaw and the flat of the lathe
bed; this makes for quick-and-dirty indexing. By careful choice of
this spacer you can get 6 divisions quickly depending on your lathe's
design. Certainly 3 div's are easy and a cross hole is a cinch.

Cross drilling does not impose a rotational force on the work piece
and I found that clamping of the lathe spindle, for this operation, is
not necessary. If you are concerned simply hold the spindle, by hand,
against the spacer pin mentioned above.

I need to visualize this. There is a hole directly under the chuck on
my lathe. I guess some kind of a wooden block etc. might do.

I was thinking of making a big handle for my 9x20 and attach it to the
other side of the spindle. I thought it would help with threading
amongst other things. I should be able to think of ways to immobilize
the handle in various positions.

My drilling spindle runs on 2 ball bearings of 3/8" bore and mounts a
threaded 1/4" capacity drill chuck. It is driven by a windshield
wiper motor through a 3-1 reduction timing belt.

Built into the lathe bench is a variable AC and DC power supply
controlled by a Variac auto transformer. This is a permanent set-up
as I use this for other work and experiments. The variable AC is fed
into a step-down transformer, rectified and smoothed with big
capacitors. This transformer can handle up to 40 Amps or so and can
supply up to 30 volts DC. Most wiper motors are very robust and
reliable and can handle this easily. In the last decade or so really
powerful radiator fan motors have become available and I would use one
of these if I were to do this again.

Once you have this device you will be amazed how easily you can carry
out what is otherwise a tedious operation.

For a small lathe a flexible shaft driven hand piece held in a
dedicated QCTH would be the way to go. Take the time to make a nice
tool that will provide use and enjoyment for a life time.

As a guide to the tool holder simply look at the commercial
toolholders that carry a fixed drill chuck. Extend the back side of
this holder by some measure and drill & bore it to take 2 ball
bearings or the hand piece, where the drill chuck is mounted.

By planning ahead this tool can be used for cross and axial offset
drilling ie holes in a bolt circle. For this though a lathe spindle
clamp is advisable.

Those are certainly considerations, thanks.

Michael Koblic,
Campbell River, BC